Three genes specifically expressed during phosphate deficiency in<Emphasis Type="Italic"> Pholiota nameko</Emphasis> strain N2 encode hydrophobins

We previously isolated 31 cDNAs corresponding to pdi [inorganic phosphate (Pi) deficiency-inducible] genes through the differential screening of a cDNA library constructed from the mycelium of Pholiota nameko strain N2 cultured in Pi-depleted medium. Among the cDNAs, pdi251, pdi263 and pdi315 were analyzed here. The deduced amino acid sequences of pdi251, pdi263 and pdi315 showed high similarity to fungal hydrophobins and genes corresponding to these cDNAs encoding P. nameko hydrophobins were designated pnh1, pnh2 and pnh3, respectively. PNH1, PNH2 and PNH3 had a conserved spacing of eight cysteine residues in hydrophobins and a hydropathy pattern characteristic of class I hydrophobins. Phylogenetic analysis showed that PNH1, PNH2 and PNH3 were phylogenetically similar and significantly related to the hydrophobin POH1 specifically expressed in fruiting bodies of Pleurotus ostreatus. Northern blot analysis indicated that, under conditions of Pi deficiency, pnh2 and pnh3 were also induced in strains N4 and N301.Communicated by U. Kück     

New simple method for small, dense LDL: development of a new quantification method and clinical significance

Small, dense LDL (S LDL) is regarded as a significant risk factor for coronary heart disease (CHD) and has also been reported its high appearance in type 2 diabetic patients. Although ultracentrifugation and electrophoresis based methods are currently used for the measurement of S LDL, such methods are either too laborious or expensive for clinical use. We have developed a simple method for quantification of S LDL. The new method consists of two steps; first to filter out large buoyant LDL and other apoB-containing lipoproteins by forming aggregates of these unintended lipoproteins with a heparin-manganese based reagent; and second to measure S LDL-cholesterol (S LDL-C) in the penetrate solution, the mixture of HDL and S LDL, on automated general chemistry analyzers. Comparison with the ultracentrifugation method yielded a correlation coefficient of 0.900 and an equation of y = 1.090x-1.8 (n = 146). Positive correlation was observed with total LDL-C level and also with triglyceride level (r = 0.782 and r = 0.526, respectively) while negative correlation was observed with LDL particle size (r = 0.658). As for the study with various types of hyperlipidemia sample, the highest level of S LDL-C was observed in combined hyperlipidemia patients. Patients with CHD had higher S LDL-C than control group (45.2 +/- 22.1 in the CHD vs. 36.7 +/- 16.9 in the control), however no difference was seen in total LDL-C level between the two groups (117.6 +/- 35.0 in the CHD vs. 115.7 +/- 30.1 in the control). Patients with type 2 diabetes also showed higher S LDL-C (54.0 +/- 22.7). S LDL-C/LDL-C ratios were also significantly higher in CHD patients and in type 2 diabetes patients than the control group (39.9 +/- 16.7 in the CHD, 37.6 +/- 13.0 in the type 2 diabetes and 31.0 +/- 9.9 in the control). Our findings suggest that this method can measure S LDL reliably with a simple procedure and that the analysis of S LDL-C can give a better index for the risk assessment of CHD than total LDL-C.     

The point mutation of tyrosine 759 of the IL-6 family cytokine receptor gp130 synergizes with HTLV-1 pX in promoting rheumatoid arthritis-like arthritis

Rheumatoid arthritis (RA) is a polygenic autoimmune disease. The autoimmunity develops from synergistic actions of genetic and environmental factors. We generated a double-mutant mouse by crossing two murine models of RA, a gp130 mutant knock-in mouse (gp130F759/F759) and an HTLV-1 pX transgenic mouse (pX-Tg), in a C57BL/6 background, which is resistant to arthritis. The mice spontaneously developed severe arthritis with a much earlier onset than the gp130F759/F759 mice and with a much higher incidence than did the pX-Tg mice. The symptoms of gp130F759/F759 mice, including lymphoadenopathy, splenomegaly, hyper-gamma-globulinemia, autoantibody production, increases in memory/activated T cells and granulocytes in the peripheral lymphoid organs, and a decrease in the class II MHC(bright) CD11c+ population, were augmented in the double mutants. Marked reductions in incidence, severity and immunological abnormalities were seen in the triple mutant, IL-6-/-/gp130F759/F759/pX-Tg, indicating that the arthritis in the double mutant is IL-6 dependent. gp130F759/F759/pX-Tg is a unique mouse model for RA.     

Presence of human herpesviruses in young children with acute otitis media

Some herpesviruses have been detected in middle ear fluid (MEF) of patients with acute otitis media (AOM), but their role in middle ear disease is unknown. We examined 73 middle ear fluid samples from 73 children with acute otitis media for the presence of four major herpesviral DNA, respiratory viral genomes, and bacterial DNA by multiplex polymerase chain reaction (PCR). Herpesviruses were detected in 16 specimens (22%), with 18 viral infections were identified overall. Respiratory viruses were detected in 35 specimens (48%), 39 viral infections overall. Bacterial DNA was detected in 51 specimens (70%), 60 bacterial infections overall. Clinical outcome was compared in patients with and without herpesvirus DNA, respiratory viral genomes, or bacterial DNA. Progression to otitis media with effusion (OME) was more common when herpesviral DNA was present. Presence of herpesvirus DNA may reflect an immunocompromised state that may make it difficult to eliminate bacteria from the middle ear after infection.     

Optical mapping of neural responses and their gamma-aminobutyric acid-ergic inhibitory effects in the auditory brainstem of early postnatal mice

gamma-Aminobutyric acid (GABA)ergic neurons play important tropic and modulatory roles in the auditory pathway, especially in the early stage between postnatal Days 0 and 5. The effects of GABA and GABAa receptor antagonist were observed in this experimental study. Numerous histological and electrophysiological studies have been performed on the contribution of GABA to the auditory pathway; however, the spatio-temporal patterns of excitatory propagation and the relationships between GABA receptor and excitatory propagation have yet to be reported. Using an optical recording technique and a voltage-sensitive dye, the spatio-temporal patterns of excitatory propagation were observed in the auditory brainstem slices of early postnatal mice. A bath containing 50 microM GABA was applied, which largely inhibited the excitatory activities along the vestibulocochlear pathway. Bicuculline methiodide (BMI), a competitive antagonist against GABAa receptor, partially reversed the effects of GABA on the optical signals. Bath application of BMI alone helped to facilitate the depolarization course and its effect was apparent as an enlargement of the depolarized region from the cochlear nucleus and vestibular nucleus to some adjacent brainstem nuclei, as well as enhancing the amplitude of changes in the optical signals. The experimental results seem to suggest that GABAa receptors are widely distributed in an early postnatal auditory brainstem. GABA exhibited a greater modulating effect in the adjacent brainstem nuclei, which are involved in complex information processes, than that observed in the modulating primary auditory pathway. In the present experiment, significant GABAergic contributions to the optical recordings in the auditory brainstem were observed.     

Steroid injection to vocal nodules using fiberoptic laryngeal surgery under topical anesthesia

Since 1990, we have performed steroid injection into the vocal fold by fiberoptic laryngeal surgery (FLS) under local anesthesia. In this study, the usefulness of this method was evaluated in 28 patients with vocal nodules. Under monitoring using a fiberoptic laryngoscope, a curved injection needle was inserted via the oral cavity and steroid was injected. Endoscopic findings showed that the vocal nodule had disappeared in 17 patients of the 27 patients and decreased in 10 after injection. The maximum phonation time was 10.9 s before operation and 13.9 s after operation, showing a significant increase (P<0.05), and the mean flow rate also showed a significant improvement (P<0.05). The patients self-rating concerning hoarseness demonstrated great improvement after injection. This technique can be performed under local anesthesia in combination with voice therapy on an outpatient basis, and it is considered to be useful for treating vocal nodules.     

Definitive diagnosis of mitochondrial neurogastrointestinal encephalomyopathy by biochemical assays

BACKGROUND: Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is caused by mutations in the gene encoding thymidine phosphorylase (TP). The clinical manifestations of MNGIE are recognizable and homogeneous, but in the early stages, the disease is often misdiagnosed. This study assesses the reliability of biochemical assays to diagnose MNGIE. METHODS: We studied 180 patients with clinical features suggestive of MNGIE, 14 asymptomatic TP mutation carriers, and 20 controls. TP enzyme activity in the buffy coat was determined by a fixed-time method, and the plasma nucleosides thymidine (dThd) and deoxyuridine (dUrd) were assessed by a gradient-elution reversed phase HPLC method. TP was sequenced through standard procedures in patients who met the clinical criteria for MNGIE. RESULTS: Twenty-five of the 180 patients fulfilled the clinical criteria for MNGIE and had homozygous or compound heterozygous TP mutations. All had drastically decreased TP activity [mean (SD), 10 (15) nmol thymine formed. h(-1). (mg protein)(-1) vs 634 (217) nmol thymine formed. h(-1). (mg protein)(-1) for the controls]. Relative to the control mean, TP activities were reduced to 35% in mutation carriers and 65% in MNGIE-like patients. All 25 MNGIE patients had detectable plasma dThd [8.6 (3.4) micromol/L] and dUrd [14.2 (4.4) micromol/L]. Controls, carriers, and MNGIE-like patients showed no detectable plasma dThd and dUrd. CONCLUSIONS: We propose a diagnostic algorithm based on the determination of plasma dThd and dUrd, TP activity in buffy coat, or both to make a definitive diagnosis of MNGIE. Increased concentrations of dThd (>3 micromol/L) and dUrd (>5 micromol/L) in plasma or a decrease in buffy coat TP activity to 相似文献   

Mechanism of action of galantamine on N-methyl-D-aspartate receptors in rat cortical neurons

Galantamine, a new Alzheimer's drug approved in the United States, is known to inhibit acetylcholinesterase and potentiate acetylcholine-induced currents in brain neurons. However, because both cholinergic and N-methyl-D-aspartate (NMDA) systems are down-regulated in the brain of Alzheimer's patients, we studied the effects of galantamine on NMDA receptors. NMDA-induced whole-cell currents were recorded from the rat multipolar cortical neurons in primary culture. NMDA currents recorded in Mg2+-free media without addition of glycine were reversibly potentiated by bath and U-tube applications of galantamine at 10 to 10,000 nM, showing a bell-shaped dose-response relationship. However, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate currents were not affected by galantamine. The maximum potentiation of NMDA currents to approximately 130% of the control was obtained at 1 microM galantamine. The potentiation was due to a shift of the NMDA dose-response curve in the direction of lower NMDA concentrations. Glycine at 1 to 3000 nM enhanced NMDA currents, and potentiation by 1 microM galantamine and 1 to 300 nM glycine was additive. The glycine site antagonist 7-chlorokynurenic acid did not prevent the galantamine action. These results suggested that galantamine did not interact with the glycine binding site. Experiments with various concentrations of Mg2+ indicated that galantamine did not affect the Mg2+ blocking site of the NMDA receptor. PKC was involved in galantamine potentiation of NMDA currents, but protein kinase A, Gi/Go proteins, and Gs proteins were not involved. Potentiation of the activity of NMDA receptors is deemed partially responsible for the improvement of cognition, learning, and memory in Alzheimer's patients.